When Pierce, KG and Allen joined forces in 2007, they had 22 All-Star appearances and 12 All-NBA selections between them. The Boston Celtics’ current “Big Three” boast four All-Star appearances and one All-NBA selection, all of which are courtesy of Rajon Rondo.

Still, even with the obvious disparities in accolades, both trios have the responsibility of leading the C’s into a new era of basketball. While Pierce, KG and Allen helped restore Boston to respectability, Rondo, Green and Sully will be charged with leading a full-scale rebuilding project that could take several seasons.

While none of them are veterans per se, having a brand new head coach in Brad Stevens means Boston will be leaning heavily on players who have familiarity with one another and who learned under Doc Rivers’ coaching staff.

There are certainly going to be some rough moments in the 2013-14 season and the years beyond, but Celtics fans should have faith in the Rondo, Green, Sullinger trio.

They may not lead Boston to a title by themselves, but the C’s could do a lot worse than having them as building blocks.

It was uncertain how much Sullinger was going to be able to contribute in the preseason coming off of back surgery, but the second-year big man has clearly been the team’s October MVP.

Despite playing limited minutes, Sully has been a major impact player. He posted a monster 19-point, nine-rebound game against the Philadelphia 76ers and has been held below double-digit scoring just once in the first four games.

As long as Sullinger can stay healthy, he figures to be the low-post option Boston has lacked over the past few seasons.

He is a terrific rebounder, particularly on the offensive glass, and uses his strength and size to make up for his lack of sheer athleticism.

As a rookie, his rebounding rate of 17.5 was higher than Joakim Noah, Andrew Bogut and Anthony Davis among others.

The C’s desperately need a player who can consistently rack up double-digit rebounds, particularly if Kelly Olynyk thrives as a stretch 5 and emerges as the long-term starter.

Sully is more than just a banger though; he has tremendous touch around the basket and has an improving offensive game.

He should not necessarily be jacking up three-pointers, but Sullinger has a decent jumper, enough to space out a defense, and will only improve that facet of his game.

Sullinger showed flashes as a post scorer in 2012-13, he has good timing and footwork as well as the ability to get his defender off-balance.

He’s not a Kevin McHale- or Hakeem Olajuwon-type scorer on the block, but he has a decent jump-hook and a reliable fadeaway jumper.

Sullinger's shot chart heat map, per Basketball-Reference.

He also converts extremely well on offensive rebounds. He can finish well with either hand, which compensates somewhat for his lack of elevation.

Defense, particularly in the post, is going to be an area for Sully to work on, but he held opposing bigs to just 38.2 percent shooting on the pick-and-roll, according to Synergy Sports.

It’s easy to forget that Sullinger is just 21 years old and has only 45 NBA games under his belt, but he was really hitting his stride before the back injury.

With more and more big men shying away from contact and working on their finesse game, Sullinger’s physicality and unique skill set mean he should become one of the game’s better power forwards as long as he can stay healthy.

Green has not exactly inspired much confidence during his first stint as a team’s main scoring option, relying too heavily on outside shots and not attacking the basket much during the preseason.

His three-point shooting was always going to cool off from where it was last season, but Green’s struggles from the perimeter have been unprecedented for a player who has spent much of his career as a stretch 4.

While it’s fair to worry if the heir apparent to Pierce at the 3 has lost his shooting touch, Green should find a way to rebound from his shooting slump.

In the modern NBA, having a player like Green is essential. He has the ability to score off the dribble, shoot from distance and defend players like LeBron James and Carmelo Anthony for at least a few dribbles.

He’ll need to improve as an overall team defender, but playing in Stevens’ system should help with that, and he has the size and athleticism to make an impact, even as a shot-blocker.

Green's shot chart heat map, courtesy of Basketball-Reference.

Additionally, when Green is locked in on the offensive end of the floor, he can look like a top-25 player in this league.

He caught fire as a starter last season, averaging 20.1 points, 5.9 boards and 2.9 assists on 52.3 percent shooting in 17 games, and if he puts up numbers even remotely near those, the Celts will be in terrific shape.

The key for Green as a franchise cornerstone is going to be consistency, as he often struggles to find a rhythm in games and shake off poor starts. He’ll need to find a way to consistently get to the foul line and contribute in other ways when he is not scoring, a talent Pierce mastered with Boston.

At the same time, that problem is why his preseason struggles are not as concerning. Green’s game is not suited for the preseason, where a player is jerked in and out of the lineup and is playing irregular minutes.

Green does his best work when he has time to develop a rhythm and a feel for the game, which should be the case during the regular season.

He may never make an All-Star team, but if Stevens can help Green fix his mental approach to the game and become more resilient, he has a shot at being a top-10 small forward in this league for years to come.

Obviously the main issue for Rondo is health because he’s shown that when he is 100 percent he is a top-five or top-three player at his position.

Rondo was criticized in 2012-13 for padding his assist totals and phoning in some of the “less important” regular season games, but the reality is that he still turned in plenty of dominant performances.

The knock on Rondo has always been that he needs talent to succeed around him, but he carried a beleaguered Celtics team within one game of the 2012 NBA Finals by averaging 17.3 points, 6.7 boards and 11.9 assists on 46.8 percent shooting from the floor.

In those playoffs Rondo was second in minutes played behind James, first in assists and assist percentage, third in steals, and posted a PER of 22.1.

If he can return and be 80 percent of that player for the next few seasons, the C’s are in good hands.

Obviously Rondo is a superb athlete with the ability to run the floor in transition and make tough finishes at the rim, but he does not rely on his athleticism as much as players like Derrick Rose or Russell Westbrook.

Rondo has phenomenal court vision and an outstanding ability to navigate in traffic, two aspects of his game that should return fairly quickly once his rhythm returns.

Rondo's shot chart heat map, courtesy of Basketball-Reference.

Additionally, many players improve as jump shooters while recovering from knee injuries because it is really the only exercise that they can do.

Rondo has already become a borderline elite mid-range jump shooter: he shot 48 percent on 16-23 foot jumpers last season per Hoopdata. If he can add a reliable three to his game, he could earn himself the title of league’s best point guard.

Defensively, Rondo should continue to be a dominant player, he has an absurd wingspan and is excellent at reading passing lanes and forcing turnovers. He gambles too often once in a while but is generally in excellent position and should thrive in Stevens’ system.

The task for Rondo will be becoming more of a vocal leader, as he has always had Garnett and Pierce to take that role for him. The buzz on Rondo has always been that he is fairly quiet and mercurial, so he might have some trouble adjusting to the role, but finally being the face of the franchise could galvanize him heading into 2013-14.

There are a lot of obvious question marks about Rondo going forward, but with his pure talent and intelligence, the odds are good that he ends up succeeding in Boston so long as he isn’t dealt in an ill-conceived panic move.

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The Trio

Rondo, Green and Sullinger did not log much time together in 2012-13, partially due to injuries and partially because it took time for Sullinger to gain Rivers’ trust. However, the trio should be able to integrate well with one another going forward.

While Sully does post up and Green can score off the bounce, neither one needs the ball in their hands to be effective. Both of them had their moments playing alongside Rondo in the past as well, and their dynamic should not change much going forward.

The Rondo-Sully pick-and-roll should become a staple of Boston’s offense. Sully has the strength and frame to set excellent screens and is a serious threat, both to roll to the basket and to pop out for open jumpers.

Even the Green-Sullinger pick-and-roll could be effective, as it would often lead to a smaller player being forced to cover Sully or a slower-footed big trying to defend Green off the bounce.

Green is a decent rebounder, but with Sully manning the paint, the C’s should have the option of playing small with Green as a stretch 4 and Sully as a small-ball 5. This lineup would be extremely mobile and could create serious matchup issues with its shooting.

Rondo and Green are both phenomenal athletes and should be a lethal tandem in transition. One of the few things that will be immediately enjoyable about the post-Big Three era will be watching the two of them sprint down the floor.

As long as Rondo makes a successful return from his ACL tear, these three are all young and have plenty of good basketball ahead of them. Green and Rondo are just 27 years old, while the 21-year-old Sullinger is nowhere near his prime.

Though they do not necessarily compliment each other as well as the Big Three did, the shooting of Green and Sully should be able to open up driving lanes for Rondo, while he will be able to find them consistently open for easy looks on the perimeter or in the paint.

Obviously, signing all three to long-term deals will be expensive, but it shouldn’t take up nearly as much of the cap as inking Pierce, KG and Allen to extensions did during their run. The C’s with Rondo, Green and Sully should largely be a deeper team than they have been in years past.

There could still be a surprise move that breaks up this trio, whether it is a decision to completely start fresh and deal Rondo, or a trade involving Sullinger and assets for an established frontcourt player, but Boston fans should rest assured that there will be brighter days ahead if the Rondo, Green, Sully trio remains intact.